I've built like that before! As long as the weather cooperates you can make progress. What I like about a truck is the front clip comes completely off and out of the way, makes setting the engine mounts up SO much easier than in a unit body car, where you have to lower it in, measure, pull it out, cut/weld/whatever, lower in and check, maybe pull out again... Full frame (not subframe!) car is the same way. Just jack the motor up and weld or whatever with it sitting there!